Spring-wheel.



E. RAMMELSBBRG.

SPRING WHEEL.

APPLIOATION FILED sBPT.25,191a.

L10'7,355. Patented Aug. 18, 1914,

is avoided.

ERNST RAMMELSBERG, 0F DORTMUND, GERMANY.

SPRING-WHEEL incassa.

Specification of Letters Patent.

Patented Anon 18, 1914.

Application tiled September 25, 1913. Serial No. 791,696.

To all whom t may eoncem:

Be it known that I, ERNST RAMMELSBERG, a subject of the King of Prussia, of 74 Ardeystrasse, Dortmund, in Vestphalia, in the Kingdom of Prussia, Empire of Germany, architect to the Government, have invented certain new and useful Improvements in Spring-Wheels; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of my present invention is to combine the greatest simplicity of the whole wheel with the most favorable manner of iiexing the springs usually arranged between the wheel-felly and an external tire-rim. To attain these ends I provide a coiled flexionspring which embodies a novel combination of one or more pairs of plane spirals and secure the free ends of the latter in the central plane of the wheel tangentially to said wheel-felly and to said tire-rim respectively on a radial line one behind the other. The forces flexing said springs while the loaded wheel is in action are thus compelled to act in the central plane of the wheel which in this instance coincides with the plane of the coils of said spirals This manner of flexing the springs in combination with the novel features of these springs, to be more fully explained later on, assures not only a continuous line of lexure in said springs, but also reduces the tendency to creeping, always present in spring-wheels to a considerable degree, to a minimum. The two principal members of the spring-Wheel are therefore in a position to execute their movements relative to each other without jerks, whereby an excessive wear and tear of the springs as well as of other parts of the wheel Foreign matter is excluded from the springs by annular guard-rings which are detachably secured to the tire-rim and slide dust-tight and water-tight upon the lateral faces of the wheel-folly.

In the accompanying drawingz--Figure 1 is a side elevation of a spring-wheel executed in accordance with my present invention, partly shown in section. Fig. 2 is a sectional view taken on the central plane of the wheel and showing a flexion-spring with but one coil. Fig. 3 is a plan view of a double-comb shaped spring-blank. Fig. 4 is a cross-sectional view taken on line 4-4 of Fig. 1. Fig. 5 is a View similar to Fig.

2 and showing a flexion-spring with a plurality of coils.

The spokes 1, the wheel-hub 2 and theA lfelly 3 of U-shaped cross-section form the inner wheel. The metallic tire-rim 4 is of similar cross-sectional shape as the felly 3, but is kept shallower than the latter. Between the felly and the tire-rim the flexionsprings 5 are arranged. Each spring is composed of one or more pairs of plane spirals 6 as circumstances may demand and may be provided with one or more complete coils. These springs are produced from a single strip of sheet-steel which, in accordance with the blank 7 shown in Fig. 3, is provided at each end with a row of tongues 8 abutting with their in ner ends or root-s at the middle of said sheet-steel strip. In each of said rows of tongues the latter are separated from each other by slits or interstices 9 whose width equals that of'said tongues. Besides this the tongues of the one row are arranged in a staggered relation to those of the other row, or in other words, the tongues of the one row are placed opposite the slits ofthe other row. To equalize the cross-sectional area of the tongues of both rows the outer tongues of the row having the greater number of tongues are of but half the width of any one of the other tongues. To produce a flexion-spring of the novel kind the tongues of the one row are passed through the slits of the other row and coiled around a common axis in opposite directions to form at least one complete coil 10. IVhen the resilience of the spring is to be greater than that obtainable with but one coil, a plurality of coils must be formed, as indicated in Fig. 5. This can be easily accomplished since there are no obstacles which would render the formation of additional coils dificult or make this impossible. The spring shown in Fig. 4 is produced from a Y-shaped blank, as will be readily understood.

The free ends 11 of the spirals 6', coiled reversely or in opposition to each other, are each provided with an inwardly projecting nose 12. These noses are inserted into slots 13 of the clamping-blocks 14 and 15 to retain the flexion-springs in their proper position. To secure the free ends of the spirals to the felly and to the tire-rim respectively, it is only necessary to tighten the bolts 16. Said blocks and bolts are arranged in the central plane of the wheel on a radial line one behind the other. 'Io protect the bolts against shearing-strain, principally caused by the creeping action of the tire-rim 4 and the elastic tire 17 mounted thereon, the blocks 14 enter into recesses 18'of the felly 3,

whereas the blocks 15 receive the projections 19 of the 'tire-rim into their cavities 20. The tire 17'may be made of solid rubber or of any other suitable material. rIfhe blocks 15 are of about twice the lwidth as the blocks 14 because they receive the noses-12 of the spiral-halves arranged laterally of the undivided middle spiral and simultaneously serve as distance-pieces to the lateral guardrings 21, see Fig. 4. The same rule will of course hold good when for one reason or another a plurality of spirals will be attached to each side of the blocks 14, a'. e. when the flexion-spring is produced from a blank similar to the one shown in Fig. 3. The springs 5 are always arranged in pairs as plainly shown in F ig. 1 and their coils are suiiiciently kept apart to permit the necessary freedom of action between the felly and the tire-rim when the'loaded Wheel is running over rough roads. To prevent any foreign matter, as for instance dust, dirt and water, from entering the tubular space .22, wherein the flexion-springs 5 are arranged, the annular guard-rings 21 are secured to the tire-rim et by means of the bolts 23 in such a manner, that the inner edges of these rings slide freely on the lateral faces 24 of the felly 3. These joints are made dust-tight as well as water-tight by the aid of the packingerings 25 made of any suitable material and pressed against the fellyfaces by the action of the resilient metal rings 26 attached to said guard-rings.

The novel features of the springs 5 assure a satisfactory action of the wheel under the most trying conditions on rough roads, since the reversely coiled and symmetrically executed spirals of even width throughout assure an unbroken line of vfleXure from the eXtreme pointl of their free ends to their mutual starting point. These springs only react upon radially disposed forces, whereas they are altogether indifferent to forces which act parallel to the axis ofthe wheel. In view of tliesefacts it will be readily understood that a breakage of a spring can rarely occur and that when such breakage does take place. the. broken spring may be readily renewed after simply removing said guard-rings and slackening ofi' the bolts and clamping-blocks which retain the broken spring.

I claim 1. A spring-wheel of the class described consisting of an inner wheel, a tire-rim, a tire mounted on said tire-rim, coiled flexionsprings interposed between said inner wheel and said tire-rim the coils of which are formed by plane spirals forming integral tongues of a fiexionspring blank whereon they are arranged comb-fashion in rows and abutting with their inner ends in staggered relation to let the tongues of one row pass through the interstices of the other row while being coiled reversely to each other around a common axis, 'clamping-means for securing the free ends of said spirals de tachably to said inner wheel and to said tire-rim respectively, and guard-rings keep.

ing the tubular wheel-space containing said flexion-springs closed against the ingress of foreign matter.

2. A spring-wheel of the class described consisting of an inner wheel, a tire-rim encircling said inner wheel, an elastic tire mounted on said tire-rim, coiled flexionsprings interposed between said inner wheel and said tire-rim and composed of plane spirals of uniform crosssectional "area throughout, clampingemeans for detachably securing the free ends of said coiled flexionsprings to said inner wheel and to said tirerim respectively, guard-rings slidingly arranged upon the lateral faces of the felly of said inner wheel and detachably secured to said tirerim, packing-rings arranged at the .inner edge of said guard-rings, and resilient rings secured to said guard-rings and adapted to `keep said packing-rings in contact with the lateral faces of said wheel-felly to prevent foreign matter from entering the tubular space wherein said coiled iiexionsprings are arranged.

3. A spring wheel of the class described,

-comprising an inner wheel, a tire rim, a

plurality of coiled springs interposed there between, each of said springs being provided with a plurality of tongues, and with a plurality of slots, arranged opposite to the tongues and traversed thereby, and means for securing said springs to the inner wheel and to the'tire Signedifby'eiiieiat Barmen the 8th day of September 1913.

ERNST RAMMELSBERG. 

